Metal-punching machine.



G. P. THOMAS.

METAL'PUNGHING MACHINE.

ABPLIOATION FILED 001:,1 1913.

i 1 ;122,440. Patented De0.2 9,1914.-

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llIllll IIIIIIH my mm Atty ' TITE mars GEORGE P. 'rnoiaas, or GLENSHAW,PENNSYLVANIA.

METAL-PUNCHING MACHINE.

Specification of Letters Patent.

Patented Dec. 29, 1914.

Application filed October 1, 1913. Serial No. 792,850.

To all whom it may concern:

Be it known that I, GEORGE P. THOMAS, residing at Glenshaw, in thecounty of Allegheny and State of Pennsylvania, a citizen of the UnitedStates, have invented or dis covered certain new and useful Improve.

ments in Metal-Punching Machines, of which improvement the following isa specification.

It is the object of my invention to provide a metal. punching machinewith means for holding an elongate piece of work firmly in properpunching position while being punched, but which will permit of a freelongitudinal movement of the work in either direction between successivestrokes of the I,

punch.

While my invention may be employed-in machines for punching variouskinds of long work, it is particularly applicable to punching suchsections maybe largely eliminated by holding them firmly in aback-to-back position during the punching operation, the best practicebeing to attach V the ends of the sections to a spacing table and tovengage and hold them firmly during each stroke of the punch at the pointof punching. My invention finds particular application in this manner ofpunching, and is thus illustrated in the accompanying drawings, formingpart of my specification. Figure 1 of the drawings is an-elevation of aportion ofa punch. frame and reciprocating head with one form of myimproved holding means attached thereto; Fig. 2 is a lan view taken onthe broken'line II II, Fig. 1; and Fig. 3 is a side elevation of thedisclosure of Fig. 1.

Like numerals are used to designate like partsin the several figures,

The improved means which I provide for I holding the work while beingpunched comprise a movable member borne by the fixed frame of the punchand adapted in one position to engage and hold the work in properpunching position, and a second member securednto the reciprocatingpunch head and adapted upon the downward stroke of the head to move thework-engaging member to its operative position.

Referring to the particular embodiment of my invention illustrated inthe drawing, two holders, alike in every respect, are shown disposed atopposite sides of a pair of back-to-back angles 1. The movable member ofeach holder is a plunger formed of-two bars 2, slidably mounted one oneach side of a carrier block 3, and rigidly con- Knectedt o each otherby a bolt 4, having a roller 5 rotatably mounted thereon between thebars.

punching machine by bolts 7 extending into slots 8 with enlarged innerends. As willgbe readily seen the plunger bars 2 are held yieldinglyfrom engagement with' the verti-' Each block 3 is adjustably se curedtothe fixed frame or anvil 6 of thecal legs of the angles 1 by means ofsprings I 9. The means carried by the punch head and efiective on thedownward stroke thereof to move the plunger 2 to work-engaging andholding position, comprise fingers 10, secured to blocks 11, adjustablysecured to opposite sides ofthe reciprocating head 12 in the same manneras the carriers 3 are secured to the frame 6. The lower end of'thefingers 10 are tapered or provided with inclined faces 13, the relativearrangement of the parts being such that, as'the head 12 movesdownwardly, the tapered finger faces 13 will strike the rollers 5 andthus cause the-plungers to move toward the angles and I thickness ofwhich in a given size angle varies but slightly throughout its length.When thus arranged and the punching 'machine put in operation, it willbeseen that the .work will, at the successive points of punching, befirmly held during each stroke of the punch, and that between strokesthe work will be free to move in either direc- -tion.' I claim as myinvention:

In a work holder for punching machinesM jo the combination with a frame,and a reciprocating head; of a block adjustably secured Because of thevariations in width' to said frame, a plunger consisting of a pair ofbars slidably mounted one on each side of said block and held yieldinglyfrom engage ment with a piece of Work, a roller-provided connectingmember between said bars, a finger adjustably secured to said head andhuv- ,ing an inclined face adapted on the downward stroke of said headto engage the roller of said plunger connecting-member and thereby movesaid plii'nge'r to-wofk-engaging position. In testimony hereofl havehereunto set my hand. I

GEORGE P. 'II-IOlVlASw Witnesses:

PAUL N. CRITCHLOV, FRANCIS J. TomAssoN.

